The present invention relates to a video signal recording and reproducing apparatus and, more particularly, to a video signal recording and reproducing apparatus for recording and reproducing a luminance signal as a frequency-modulated signal and a chrominance signal as a signal frequency-converted into a low frequency band. The present invention also relates to a video signal recording and reproducing apparatus combined with a video camera.
In the video signal recording and reproducing apparatus using a magnetic tape as a recording medium, such as a video tape recorder (which will be shortly referred to as "VTR"), according to the prior art, as disclosed in Japanese Patent Application Publication No. 55-19116 and its corresponding U.S. Pat. No. 4,178,606, a carrier wave is frequency-modulated with a luminance signal so as to produce a signal frequency-modulated with the luminance signal (this frequency-modulated signal will be referred to as a "FM luminance signal"), and a chrominance signal is frequency-converted into a lower frequency band than that of the FM luminance signal (this frequency-converted signal will be referred to as a "down-converted chrominance signal"), so that the FM luminance signal and the down-converted chrominance signal are frequency-multiplexed, recorded on and reproduced from the recording medium.
In the video signal recording and reproducing apparatus of such type, the luminance signal is usually processed for a variety of S/N ratio improvements such as the noise reduction or dropout compensation, thus improving the picture quality of the reproduced image.
As to color difference signals, however, the chrominance signal, which is produced by the quadrature two-phase modulation of a carrier wave with the color difference signals, is directly converted into a low frequency band by frequency conversion means to form the down-converted chrominance signal. This chrominance is recorded in the magnetic recording medium. For reproductions, the down-converted chrominance signal is directly converted into a high frequency band by the frequency conversion means to provide the chrominance signal in the original carrier frequency. Since, in the video signal recording and reproducing apparatus of the prior art, each color difference signal is processed in the mode of a modulated wave, i.e., as the chrominance signal, it is difficult to reduce the noises, e.g., to clip noise pulses rising from the pedestal level or cancel the noises. Moreover, the dropout compensation is seriously difficult and is not commonly adopted because the continuity of the carrier phase in the chrominance signal has to be maintained.